BMJ Group Medical Reference
This information is for people who have osteoporosis. It tells you about calcitriol, a treatment used for osteoporosis. It is based on the best and most up-to-date research.
Does it work?
Probably. Calcitriol seems to help prevent broken bones in women after the menopause. But there isn't much evidence to show this. And this treatment can have side effects.
What is it?
If you have osteoporosis, your bones are weak and likely to break. Calcitriol is designed to help your body:
Your doctor may prescribe it to treat osteoporosis. And your doctor may prescribe it to prevent osteoporosis if you are especially likely to get it.
Calcitriol belongs to a group of drugs called vitamin D analogues. They are a stronger form of vitamin D than you get in tablets of regular vitamin D.
You need a prescription to get calcitriol. The brand name is Rocaltrol.
Your doctor may prescribe this treatment if other treatments, such as drugs called bisphosphonates, are not right for you. Some examples of those drugs are alendronate and risedronate.
Calcitriol comes as capsules. You take it twice a day. With this drug, the level of calcium in your blood can get too high. So your doctor will do regular blood tests to make sure your dose is right.
If you take calcitriol, how much calcium you get from foods and from tablets is important. If you get too much calcium, you may get side effects from calcitriol. If you get too little calcium, calcitriol won't work properly. Your doctor should advise you about how to get the right amount of calcium. 
How can it help?
If you take calcitriol you may be less likely to break a bone.
Calcitriol lowers the chances of breaking a bone by about half in women who have been through the menopause. 
Calcitriol and the other drug in this group work better than regular vitamin D in preventing broken bones in your spine. 
But not all studies show this. One summary of the research found no difference between taking calcitriol, taking calcium, and taking a dummy drug (for a placebo).